Please refer to FIG. 1, a perspective view of a conventional wafer storing container such as that disclosed in U.S. Pat. No. 4,787,508. The conventional wafer container comprises a main case 10 and a covering means 20. The main case 10 is tube-like for storing wafers (not shown), having a close end 110, and an open end 120. Several slots 130 are provided at the wall of the main case 10 from its open end 120 along its axis, so that wafers can be clipped and taken out. Threads 140 are provided on the outer periphery of the main case 10 near its close end 110.
The covering means 20 is substantially tube-like, having a close end 210 and an open end 220, for being sleeved on the main case 10. The inner periphery of the covering means 20 has threads (not shown) to be engaged with threads 140, for sealing the entire container. A circular recess 230 is formed on the close end 210. A round protrusion 240 is provided within the recess 230 to be turned to open the covering means 20.
There are some deficiencies in the conventional wafer container 1. Because wafers are not tightly secured in the container, wafers may be damaged from shaking in transportation. Furthermore, it needs additional efforts to fasten the containers. Besides, when the circular recess 230 is too narrow, a user can hardly insert his fingers into the recess 230 to turn the protrusion 240. On the other hand, if the circular recess 230 is widened to receive fingers, the outer periphery of the protrusion 240 will be reduced, therefore increases the force needed to turn the covering means 20. Another deficiency is that the container can not be re-used before all wafers in the container are taken out, which increases the cost in maintaining a lot of containers in factories.